A file represents a sequence of bytes and these file’s is used to store information. There are various different operations that we can be performed on a file are:
- Creation of a new file (fopen with attributes as “a” or “a+” or “w” or “w++”)
- Opening an existing file (fopen)
- Reading from file (fscanf or fgetc)
- Writing to a file (filePointerrintf or filePointeruts)
- Moving to a specific location in a file (fseek, rewind)
- Closing a file (fclose)
Functions for file handling
There are various predefined functions available for handle file. Some of them mentioned below:
| Function | Description |
|---|---|
| fopen() | Used for opens new or existing file |
| fprintf() | Used for write data into the file |
| fscanf() | Used for reads data from the file |
| fputc() | Used for writes a single character into the file |
| fgetc() | Used for reads a single character from file |
| fclose() | Used for closes the file |
| fseek() | sets the file pointer to given position |
| fputw() | Used for writes an integer to file |
| fgetw() | Used for reads an integer from file |
| ftell() | returns current position |
| rewind() | sets the file pointer to the beginning of the file |
Create or Open Files
We can create a new file or open an existing file by using fopen() function. To create a new file or open an existing file syntax is:
FILE *fopen( const char * filename, const char * mode );
Here, filename is a string literal and use one of the following modes in the fopen() function if you are working with text file:-
| File Mode | Meaning of Mode |
|---|---|
| r | opens a file in read mode. If the file does not exist, fopen() returns NULL. |
| w | opens a file in write mode. If the file does not exist, fopen() returns NULL. |
| a | opens a file in append mode ( Data is added to end of file). f the file does not exists, it will be created. |
| r+ | opens a file in a both read and write mode. If the file does not exist, fopen() returns NULL. |
| w+ | opens a file in both read and write mode. If the file exists, its contents are overwritten. If the file does not exist, it will be created. |
| a+ | opens a file in both read and write mode. If the file does not exists, it will be created. |